Morin F C, Egan E A, Norfleet W T
Department of Pediatrics, University of Buffalo, New York 14214.
Pediatr Res. 1988 Dec;24(6):696-700. doi: 10.1203/00006450-198812000-00009.
This study was performed to determine whether prostaglandins play a role in the increase in pulmonary blood flow in the fetal lamb caused by an increase in oxygen tension similar to that occurring at birth. To increase fetal oxygen tension without ventilating the lungs, nine pregnant ewes with chronically instrumented fetuses were exposed to 100% oxygen at 3 atmospheres absolute pressure for 20 min in a hyperbaric chamber. This exposure increased pulmonary arterial oxygen tension in the nine fetuses from 20 +/- 1 to 54 +/- 9 torr. It increased pulmonary blood flow from fetal to newborn values, 31 +/- 3 to 295 +/- 20 ml/kg/min. It did not change pulmonary arterial pressure, 52 +/- 2 torr during normoxia and 50 +/- 2 torr during hyperoxia. Treating five of these fetuses with 3.2 +/- 0.4 mg/kg of indomethacin during hyperbaric oxygenation did not alter these effects (PO2 = 51 +/- 8 torr, pulmonary blood flow = 283 +/- 13 ml/kg/min, and pulmonary arterial pressure = 48 +/- 2 torr). We conclude that the increase in pulmonary blood flow caused by an increase in oxygen tension in the fetus is not maintained by prostaglandins.
本研究旨在确定前列腺素是否在类似出生时发生的氧分压升高所引起的胎羊肺血流量增加中起作用。为了在不使肺通气的情况下增加胎儿的氧分压，将9只带有慢性仪器监测胎儿的怀孕母羊置于高压舱中，在3个绝对大气压下暴露于100%氧气中20分钟。这种暴露使9只胎儿的肺动脉氧分压从20±1托增加到54±9托。它使肺血流量从胎儿水平增加到新生儿水平，从31±3毫升/千克/分钟增加到295±20毫升/千克/分钟。它没有改变肺动脉压，常氧时为52±2托，高氧时为50±2托。在高压氧合期间，用3.2±0.4毫克/千克的吲哚美辛治疗其中5只胎儿并没有改变这些效应（氧分压=51±8托，肺血流量=283±13毫升/千克/分钟，肺动脉压=48±2托）。我们得出结论，胎儿氧分压升高所引起的肺血流量增加并非由前列腺素维持。
